Sarnia Fire and Rescue Services responded to an early morning fire on East Street just south of London Road Tuesday.
The blaze broke at the one storey home out just after 6 a.m.
Fire officials said the homeowner returned home to see flames coming from the back of the house. Firefighters were able to keep the flames contained to one room and no injuries are reported.
Damage is estimated at about $20,000.
The cause was traced to a light switch and deemed electrical in nature.
